The sysctl values didn’t do it for me, but adding
zeroconf:
default_interface: true
to configuration.yaml and restarting the container got rid of the error. From the zeroconf integration page it was my understanding this makes it use only main ip instead trying to bind to 0.0.0.0 which causes the issue under docker.
Since then I restarted the RPi twice for unrelated reasons and the zeroconf error hasn’t showed up.